Perhaps you should try some spelling variations:
cao khoa » lao khoa, bao khoa, cac khoa
hanh vai » hanh vi, hanh va, hanh tai
cao hoa » cao hoat, cau hoa, cao hoc
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
xuc va » tuc va, luc va, xac va
vai va » mai va, dai va, hai va
thiet » thieu

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((cao hoa) OR (cao khoa)). hieu ve chat ((xuc va) OR (duc va)) hanh vai va thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((cao hoa) OR (cao khoa)). hieu ve chat ((xuc va) or (duc va)) hanh vai va thiet~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((cao hoa) OR (cao khoa)). hieu ve chat ((xuc va) or (duc va)) hanh vai va thiet*.